Dry ore-concentrating table



Dec. 30, 1969 R. A. STOLLE ,6

' DRY ORE-CONCENTRATING TABLEv Filed June 7, 1967 2 Sheets-Sheet 1 INVENTOR RA YMO/VD 4. 57'0LLE Bag/5%.

ATTORNEY '30, 1969 RA. s'roLLE I Q DRY ORE-CONCENTRATING TABLE 2 Sheets-Sheet 2 Filed June 7, 1967 I I INVENTOR RAYMOND A. STOLLE BY fiw/ Arrow/5y United States Patent 3,486,620 DRY ORE-CONCENTRATING TABLE Raymond A. Stolle, P.O. Box 470, Red Mountain, Calif. 93558 Filed June 7, 1967, Ser. No. 644,165 Int. Cl. B07b 3/04, 1/40 US. Cl. 209-467 4 Claims ABSTRACT OF THE DISCLOSURE A vibrated, ore-concentrating table having a deck slanted downwardly toward one side, said deck being comprised of a plurality of riifies across which the ground ore material moves, while air forced through a plurality of openings in the rifile can act only on and raise the lighter, tailing portions or particles of the ore material to continue their progress over the rifiles toward the low side of the deck while the heavier and desirable particles, unaffected by said air, continue their longitudinal movement along the deck toward the end of the table. Adding a quantity of heavy material to the ore material provides the latter wih a preponderance of heavy particles which tend to crowd the lighter particles upwardly during table vibration and into the air streams forced through the riffles. Magnetism may be used to separate the concentrate of the heavy particles and the added material adapted for re-use in a subsequent operation.

BACKGROUND OF THE INVENTION It is the consensus of opinion in the mining and milling business that dry concentration methods and dry concentrators are neither practical nor economically efficient. The principle of gravity concentration entails the use of air to lift the particles of ground ore material during vibration of the deck. This air, in relation to their weight, will have a lifting effect on the lighter proportion of the heavier particles also, and will cause them to become incorporated and be discarded with the tailings, at a substantial loss of valuable concentrate. This loss is due to the prior known methods entailing the use of fabrics, screens, or slotted coverings which allowed even the heavier particles to be lifted high enough to cause their above-mentioned loss in the tailings.

An object of the present invention is to provide novel and improved rifile means which overcomes the above faults in earlier concentrators by keeping the heavier ore particles out of the influence of the air and only affecting the lighter particles.

Another object of the invention is to provide a novel and eflicient method for concentrating ground ore by adding to the same a quantity of magnetic material of a known specific gravity approximating the specific gravity of the values in the ore, utilizing the combination of said material and values to crowd out all of the lighter materials in the ore during concentration, thereby causing said lighter materials (the tailings) to be more efliciently separated from the concentrate which comprises the added material and the values of the ore. Then, by magnetism, said material and values may be inexpensively separated.

This invention also has for its objects to provide a novel, economical and convenient method or process of superior utility, and to provide apparatus that is positive in operation, convenient in use, easily installed in working position and easily disconnected therefrom, economical of manufacture, relatively simple, and of general superiority and serviceability.

The invention also contemplates novel combinations of method steps as well as novel details of construction and novel combinations and arrangements of parts, which 3,486,620 Patented Dec. 30, 1969 "ice will appear more fully in the course of the following description, which is based on the accompanying drawings. However, said drawings merely show, and the following description merely describes, the invention with respect to preferred methods and apparatus, the same being given by way of illustration or example only.

SUMMARY OF THE INVENTION BRIEF DESCRIPTION OF THE DRAWINGS In the drawings, like reference characters designate similar parts in the several views.

FIG. 1 is a plan view of a dry ore-concentrator provided with the present ore-concentrating improvements.

FIG. 2 is a broken side elevational view thereof.

FIG. 3 is an enlarged, fragmentary plan view of a riflle and air-guiding deck element, aplurality of which comprise the deck shown in FIGS. 1 and 2.

FIG. 4 is a cross-sectional view as taken on the line 4-4 of FIG. 1.

FIG. 5 is a further enlarged longitudinal view as taken on the line 5--5 of FIG. 3.

FIG. 6 is a cross-sectional view as taken on the plane of the line 66 of FIG. 1, the view being double the size of FIG. 1.

FIG. 7 is a view similar to FIG. 4, of another form of riflle and air-guiding deck element.

FIG. 8 is a fragmentary plan view thereof, to a reduced scale.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The concentrator 5, illustrated in FIGS. 1, 2 and 8, typically comprises a generally rectangular frame 15 having a horizontal top 16 that mounts the vibratory frame 6 and which, in any suitable manner, mounts an electric motor 17 (or other prime mover), the source of compressed air, here shown as a centrifugal fan 8 and having a flexible outlet 18, a drive connection 19 from said motor to said fan, an eccentric 20 with a rod extension 21 connected to the frame 6, and a drive connection 22 from said motor to said eccentric.

The vibratory frame 6 is mounted on the ends of links 23 which are journaled in bearings 24 on the frame top 16. Said mounting of the frame 6 is such as to have a vibratory movement longitudinally of the concentrator according to the reciprocating movement of the eccentric 20.

The table 7 is disposed above the frame 6, is connected at one end to the flexible outlet 18, and is closed at the other end 25. Said table has a bottom 26 and sides 27 which, together with the end 25, define a chamber 28. As shown in FIG. 1, one table side 27 extends for the full length of the table, while the opposite or rear side is slanted, as at 29, imparting a wedge shape to the table so that said end 25 is relatively narrower than the end to which the fan outlet 18 is connected. The deck 9 extends over the chamber 28 and, as will be seen hereinafter, affords the only openings for escape of the compressed air entering from the fan outlet 18.

As best seen in FIG. 6, one side of the table 7 and the deck 9 are connected by hinges 30 to one side of the frame 6, and a turnbuckle 31, or similar adjustable means, connects the opposite sides of the table 7 and frame 6 so the table may be adjusted to have a transverse slant downward toward the hinged side. A tailing board 32 is provided at the hinged side of the table.

A hopper 33 for ground ore may be provided on the table 7 at the rear end thereof adjacent the end at which the air is admitted. The table may carry said hopper.

The deck 9 comprises a plurality of elements 34 in which are provided the rifiies 10 and the air-passing means 11, the same being advantageously formed of stamped and drawn sheet metal and assembled in side-by-side contiguous arrangement to extend generally longitudinally of the deck 9 or, as shown in FIG. 1, at a slight angle toward the rear side of the concentrator, said elements 34, thereby, terminating at the sloping rear side 29 at which side a chute 35 receives the concentrate values of the ore conducted thereto during operation of the concentrator. Concentrate will also be discharged from the ends of the elements 34 which terminate at the end 25 of the table.

Each element 34 has a channel cross-sectional form (as in FIGS. 4 and 7) having a bottom 36 and side flanges which are the riifies 10 over which material passes during operation. While said riffie flanges may vary in height, in practice, for concentrating precious metals, as gold, tungsten, etc., they are high.

The bottoms 36 of the elements 34 serve as the surface of the deck 9 and upon which the ore is deposited from the hopper 33. Each said bottom 36 is provided 'with a series of transverse slots 37 or, as shown in the drawing, two series of slots 37, each slot being defined by a raised rim 38 preferably formed by the metal of the bottom 36 being upwardly extruded. The height of the rims 38 may vary, but is preferably shallow, in the nature of but nevertheless causing the slots 37 to be raised above said bottom 36 so that longitudinal channels 39 are formed between each riffle flange 10 and the adjacent ends of each slot rim 38. Channels 40 are also formed between the adjacent ends of the slot rims of two series of slots.

If desired, as shown in FIGS. 7 and 8, one channel, as channel 39a may be wider than the other channel. The channels 39a, being larger, provide more space for values. Therefore, as shown in FIG. 7 said wider channels 39a are placed on the low side.

Due to the transverse slant of the table 7, the deck 9 has a similar transverse slant downwardly from the hopper 33. The bottoms 36 of the elements 34, as shown best in FIGS. 4 and 7, are sloped downwardly toward the tailing board 32 on the plane of said deck, accordingly.

Operation Vibration of the table 9 causes the ground ore material deposited from the hopper 33 to pulsate up and down. The air forced through the slots 37 exiting from the rims 38 above the level of the bottom 36 can have no effect on the heavier particles, since the same remain in the longitudinal channels 39 or 3911 and 40 between the slots. The lighter particles, being subject to such pulsation, are raised above the rims 38 and are subject to the jet action of the air. Due to the slope of the deck, the jets of air, as the lighter fractions pass thereover, promote transverse movement over the rifiles 10 until the same, as tailings, arrive at and are shed by the tailing board 32. Since the heavier values remain on the bottom against the rifile flanges and cannot be subjected to air jet action, they will follow the riflies 10 until they reach the concentrate-disposal gates at the top of the deck where the chute 35 is shown.

The method above described is dry. The ability to obtain a high-grade concentrate, especially on dry concentrators, is largely dependent on the proportion of values to tailings. If this proportion were to be made more favorable by increasing the values as by adding a material of similar weight or specific gravity to the ore, a more efiicient separation of tailings from the values may be effected.

Thus, if in the above concentrator, a magnetic, or but slightly magnetic material were added to the ore material, the same would combine with the values to form a mass of heavy particles that would so crowd the lighter particles that they could not settle into the channels that conduct the values to the disposal gates. Therefore, the air jets would be operating on said exposed particles, directing them to the tailings discharge.

A magnetic separator can easily separate the values from this material, which then can be re-used for the same purpose in a closed-circuit or batch arrangement.

The above is particularly efiicient when working ores of very low grade, and provides the mining and milling industries with an inexpensive, yet highly efficient, method of ore concentration. For instance, in working low-grade deposits of placer tungsten and gold, a material such as garnet or of comparable specific gravity and hardness, may be added to the ore in any desired proportion that will effect crowding action as above mentioned. If as much garnet as expected values in the ore is added, the separation jet air action would be approximately twice as eflicient. The efliciency will increase as greater proportions of garnet are used, until the economics of the operation are satisfied.

While the foregoing illustrates and describes what is now contemplated to be the best mode of carrying out the invention with respect to both the method and apparatus, the same is, of course, subject to modification without departing from the spirit and scope of the invention.

I claim:

1. In a vibratory dry ore-concentrating table that has a hollow interior into which compressed air is fed and which is adapted to be disposed at a downward slope from the side thereof provided with a hopper to feed ground ore material onto the opposite elevated side of the table, a deck comprising:

(a) a bottom having a coplanar downward slope according to the slope of the table,

(b) a plurality of riflies in spaced relation across the deck and extending mainly longitudinally of the table,

(c) at least one longitudinal row of transversely slotted openings in said bottom between and spaced from the riflies, for passing air from the interior of the table in an upwardly outward direction, and

(d) said bottom being provided with upwardly extending rims around the openings and which are lower than the rifiies and, thereby, are in elevated position above said deck bottom lower than the tops of the riffles,

(e) the spaces between the riffles and the row of openings comprising uninterrupted channels that conduct the heavier values of the ore material toward an end of said deck during vibration of the table, and

(f) the lighter, tailing portions of the ore material being raised by the vibrating table above the deck bottom and into the path of the air exiting from the elevated openings to be raised above the rifiies for transverse displacement from between two adjacent riffles to a space between the lower of said riflies and the lower riflle adjacent thereto.

2. In an ore-concentrating table according to claim 1, the row of slotted openings'being spaced farther from the lower riflle than from the adjacent more elevated rifiie, thereby providing wider value-conducting channels on the lower side of the space between the riflles than on the more elevated side.

3. In an ore-concentrating table according to claim 2, each row of openings and the rims of the openings being longitudinally divided into two transversely spaced rows of shorter openings.

4. In an ore-concentrating table according to claim 2 in which the deck comprises a plurality of channel elements, each channel element comprising:

(a) a web forming a portion of said bottom,

(b) side flanges forming the riflies, and

(c) each web having at least one longitudinal row of 5 openings with an upwardly extending rim therearound.

References Cited UNITED STATES PATENTS 1,262,603 4/ 1918 Tyler 209467 1,505,734 8/ 1924 Stebbins 209467 2,128,918 9/ 1938 Dickerson 209467 2/ 1943 Brusset 209467 2/ 1968 Eveson 209467 U.S. Cl. X.R. 

